1. Field of the Invention.
The present invention relates to a film and sheet material storage device and particularly to an improved reel assembly formed by reel components held in engagement by axial forces where the reel components can be stacked in a compact manner before assembly and after disassembly.
2. Description of the Prior Art.
Reel designs were at one time used primarily by the motion picture and television industries for storage of film. These designs did not change over time, basically adhering to a preassembled two-walled, central hub design. However, the recent explosion of microcomputers and electronics has created an additional use for reel designs. Today, electronic components and computer chips, which are relatively small in size, are stored on a compartmentalized carrier tape which is taken up onto a reel. The carrier tape may also be formed by two separate gummed layers, joined with the gummed faces being in face-to-face engagement wherein electronic components may be stored therebetween. The phrase "carrier tape", as used herein, is intended to cover all forms of film, tape, ribbon and substrate which are suitable for take up on a reel.
As a result, a new reel market has been created with storage concerns never raised by the film industry. The tremendous amount of electronic gadgetry which is being sold, requires an equally tremendous amount of electronic components, which, in turn, translates to a great number of reels. Due to the design of a reel, a large amount of volume is required to store the reel before and after use. In response to this problem, manufacturers began selling stackable reel components which, with minor assembly, could form a reel. The prior art reel components are formed with a central hub and a surrounding side wall extending circumferentially therefrom to a predetermined diameter. To form a reel, two of the prior art reel components are typically glued, ultrasonically welded or joined through the engagement of cooperating retaining means formed on the surface of the hub, such as that found in U.S. Pat. No. 4,726,534 (hereinafter "'534 patent") to Dean B. Chenoweth.
When stacked, however, spaces are formed between neighboring reel components. Prior art hub designs did not permit full face-to-face engagement between neighboring, stacked reel components, since the hubs were not formed to define an inner surface able to accommodate the diameter of the outer surface of the hub of a neighboring stacked reel component. Thus, prior art reel components allowed nesting only to the extent the inner surface of the hub was equal to or larger than the outer dimension of the hub. As a result of the spaces being formed between stacked reel components, tremendous volume is required to store a relatively few number of reel components. Shipping costs and waste carting fees are relatively high for objects having a low weight and encompassing a high volume. Thus, there is a need for reel components which can be stacked in a compact manner requiring minimal volume.
The space formed between the prior art reel components, however, is necessary for some prior art designs. For example, the cooperative retaining means of the '534 patent project from the hub and would prevent perfect nesting between reel components. Thus, the space between the reel components forms a housing for the retaining means. A reduction in the height of the space would require retaining means which would not prevent contact between the hub of one reel component and the hub of a second reel component. Therefore, there is a need for a cooperative retaining arrangement which would not prevent the compact stacking of reel components.
Also, reel components which can be formed through the engagement of cooperating retaining means are more desirable than those requiring gluing or ultrasonic welding. Labor, time and assembly inaccuracies are reduced where a reel assembly can be formed through the engagement of cooperating retaining means. Since the take up and winding of carrier tape exerts rotational forces on a reel assembly, the rotational orientation of engaged retaining means, such as that found in the '534 patent, results in increased loading and a greater likelihood of failure in the retaining means members. There is a need for a reel assembly which is held in engagement by cooperating retaining means oriented to exert and receive axial forces.
Reel components are preferably molded from recyclable plastic. Unfortunately, assembled reels require even more volume for shipping than the previously discussed prior art stacked reel components. Unlike the individual reel components, assembled reels are not capable of nesting at all. Accordingly, costs for storage and removal to recycling are relatively high considering the necessary volume. Indeed, there is a need for a reel assembly which can be readily disassembled, allowing individual reel components to be stacked.
In summary, there is a need for a reel component formed to require minimal space when stacked and having cooperative retaining means which are aligned to transmit and receive axial forces, do not prevent compact stacking and allow for disengagement.